Icom IC-7400, Service Manual, Page: 24 / 92

*This output level of a standard signal generator (SSG) is indicated as SSG’s open circuit.
RX PEAK
RECEIVER
TOTAL GAIN
NOISE
BLANKER
5 - 8
5-4 RECEIVER ADJUSTMENTS
ADJUSTMENT
ADJUSTMENT ADJUSTMENT CONDITION
MEASUREMENT
VALUE
POINT
UNIT LOCATION UNIT ADJUST
1
2
3
1
1
2
• Displayed freq. : 14.100000 MHz
• Mode
: USB
• Set following selections, controls
and functions as:
[RF/SQL] : Center
[PITCH] : Center
[AGC] : OFF , [ATT] : OFF
[NB] : OFF , [RIT] : OFF
PBT1 : Center, PBT2 : Center
[P.AMP]
: P.AMP1
IF Filter : 2.4 kHz
[NR] switch : OFF
[NOTCH] switch: OFF
• Preset L215 (RF unit) to 2 rotation
downside from top of the coil’s case.
• Connect an SSG to [ANT1] con-
nector and set as:
Frequency : 14.101500 MHz
Level : 10 µV* (–87 dBm)
Modulation : 1 kHz/±3.5 kHz dev.
• Receiving
• Mode : FM
• Filter : 15 kHz
• Set an SSG as :
Frequency : 14.100000 MHz
Level : 1 mV* (–47 dBm)
Modulation : 1 kHz/±5.0 kHz Dev.
• Receiving
• Displayed freq. : 0.03000 MHz
• Set an SSG as :
Level : OFF
• Receiving
• Displayed freq. : 14.100000 MHz
• Mode
: USB
• Filter : 2.4 kHz
• [P.AMP] : OFF
• Set an SSG as :
Frequency : 14.101500 MHz
Level : 160 mV* (–3 dBm)
Modulation : 1 kHz/±5.0 kHz dev.
• Receiving
• Displayed freq. : 14.100000 MHz
• Mode
: USB
• [P.AMP] : P.AMP1
• [NB] : OFF
• [NB LEVEL] : 50%
• Set an SSG as :
Frequency : 14.101500 MHz
Level : 18 µV* (–82 dBm)
Modulation : OFF
and apply following signal to [ANT1]
connector.
• Preset R200 (MAIN unit) to the 12
o’clock position.
• Receiving
• [NB] : ON
• Receiving
Rear
panel
MAIN
MAIN
Connect an AC milli-
volt meter to [EXT
SP] connector with
an 8
Ω
load.
Connect an distortion
meter to [EXT SP]
connector with an
8
Ω
load.
Connect an AC milli-
volt meter to [EXT
SP] connector with
an 8
Ω
load.
Connect an oscillo-
scope to the check
point CP1460.
Connect an oscillo-
scope to the check
point CP200.
Maximum audio output
level
Minimum distortion
level
Minimum noise output
level
4.0 Vp-p
Maximum noise level
At the point where the
voltage just reduces.
RF
MAIN
MAIN
L252,
L251
,
L242,
L241
,
R218
R1469
L201,
L202,
L203
,
R200
100 msec.
1 msec.